Evaluation of Fluvial Sediment Transport Equations for Overland Flow

Sediment transport capacity was measured under a range of conditions in two types of overland flow: shallow uniform flow in the absence of rainfall, and shallow flow affected by rainfall impact. The abilities of six fluvial sediment transport equations to represent each dataset are evaluated. For both flow types, common aspects of equation performance include poor representation of sediment transport thresholds, underprediction of transport rates, and significant scatter about measured values. These problems, particularly the equations’ inability to predict transport thresholds, are more evident with the rain-impacted flow data. Only the Schoklitsch equation is suitable for uniform overland flow without rain-impact, and none are suitable for rain-impacted overland flow.